A traditional machine vibration analysis channel typically includes an analog front-end, an analog-to-digital converter (ADC), and a digital signal processor (DSP) or microcontroller. The analog front-end usually consists of a vibration sensor, an input amplifier, an AC coupling amplifier, an analog integrator, a variable-gain amplifier, a low-pass anti-aliasing filter, and a high-pass filter. Such implementations of front-end signal conditioning functions in the analog domain cause numerous problems. Calibration is required due to component variations that cause the sensitivity and bandwidth of the signal path to vary. Analog components require relatively large amounts of space on a printed circuit board, and they consume large amounts of power for low-noise designs. They are also somewhat limited in terms of programmability. For systems designed for use in hazardous environments, reduced voltage and capacitor allowances force tradeoffs in noise and bandwidth in the analog signal path.
What is needed, therefore, is a machine vibration measurement system in which the front-end signal conditioning functions are performed in the digital domain, such as in a field programmable gate array (FPGA).